# Python code to implement Conway's Game Of Life 
import argparse 
import numpy as np 
import matplotlib.pyplot as plt  
import matplotlib.animation as animation 
  
# setting up the values for the grid 
ON = 255
OFF = 0
vals = [ON, OFF] 
  
def randomGrid(N): 
  
    """returns a grid of NxN random values"""
    return np.random.choice(vals, N*N, p=[0.2, 0.8]).reshape(N, N) 
  
def addGlider(i, j, grid):
  
    """adds a glider with top left cell at (i, j)"""
    glider = np.array([[0,    0, 255],  
                       [255,  0, 255],  
                       [0,  255, 255]]) 
    grid[i:i+3, j:j+3] = glider 

def addGosperGliderGun(i, j, grid): 
  
    """adds a Gosper Glider Gun with top left 
       cell at (i, j)"""
    gun = np.zeros(11*38).reshape(11, 38) 
  
    gun[5][1] = gun[5][2] = 255
    gun[6][1] = gun[6][2] = 255
  
    gun[3][13] = gun[3][14] = 255
    gun[4][12] = gun[4][16] = 255
    gun[5][11] = gun[5][17] = 255
    gun[6][11] = gun[6][15] = gun[6][17] = gun[6][18] = 255
    gun[7][11] = gun[7][17] = 255
    gun[8][12] = gun[8][16] = 255
    gun[9][13] = gun[9][14] = 255
  
    gun[1][25] = 255
    gun[2][23] = gun[2][25] = 255
    gun[3][21] = gun[3][22] = 255
    gun[4][21] = gun[4][22] = 255
    gun[5][21] = gun[5][22] = 255
    gun[6][23] = gun[6][25] = 255
    gun[7][25] = 255
  
    gun[3][35] = gun[3][36] = 255
    gun[4][35] = gun[4][36] = 255
  
    grid[i:i+11, j:j+38] = gun 
    
def update(frameNum, img, grid, N): 
  
    # copy grid since we require 8 neighbors  
    # for calculation and we go line by line  
    newGrid = grid.copy() 
    for i in range(N): 
        for j in range(N): 
  
            # compute 8-neghbor sum 
            # using toroidal boundary conditions - x and y wrap around  
            # so that the simulaton takes place on a toroidal surface. 
            total = int((grid[i, (j-1)%N] + grid[i, (j+1)%N] + 
                         grid[(i-1)%N, j] + grid[(i+1)%N, j] + 
                         grid[(i-1)%N, (j-1)%N] + grid[(i-1)%N, (j+1)%N] + 
                         grid[(i+1)%N, (j-1)%N] + grid[(i+1)%N, (j+1)%N])/255) 
  
            # apply Conway's rules 
            if grid[i, j]  == ON: 
                if (total < 2) or (total > 3): 
                    newGrid[i, j] = OFF 
            else: 
                if total == 3: 
                    newGrid[i, j] = ON 
  
    # update data 
    img.set_data(newGrid) 
    grid[:] = newGrid[:] 
    return img

# main() function 
def main(): 
  
    # Command line args are in sys.argv[1], sys.argv[2] .. 
    # sys.argv[0] is the script name itself and can be ignored 
    # parse arguments 
    parser = argparse.ArgumentParser(description="Runs Conway's Game of Life simulation.") 
  
    # add arguments 
    parser.add_argument('--grid-size', dest='N', required=False) 
    parser.add_argument('--mov-file', dest='movfile', required=False) 
    parser.add_argument('--interval', dest='interval', required=False) 
    parser.add_argument('--glider', action='store_true', required=False) 
    parser.add_argument('--gosper', action='store_true', required=False) 
    args = parser.parse_args() 
      
    # set grid size 
    N = 100
    if args.N and int(args.N) > 8: 
        N = int(args.N) 
          
    # set animation update interval 
    updateInterval = 50
    if args.interval: 
        updateInterval = int(args.interval) 
  
    # declare grid 
    grid = np.array([]) 
  
    # check if "glider" demo flag is specified 
    if args.glider: 
        grid = np.zeros(N*N).reshape(N, N) 
        addGlider(1, 1, grid) 
    elif args.gosper: 
        grid = np.zeros(N*N).reshape(N, N) 
        addGosperGliderGun(10, 10, grid) 
  
    else:   # populate grid with random on/off - 
            # more off than on 
        grid = randomGrid(N) 
  
    # set up animation 
    fig, ax = plt.subplots() 
    img = ax.imshow(grid, interpolation='nearest') 
    ani = animation.FuncAnimation(fig, update, fargs=(img, grid, N, ), 
                                  frames = 10, 
                                  interval=updateInterval, 
                                  save_count=50) 
  
    # # of frames?  
    # set output file 
    if args.movfile: 
        ani.save(args.movfile, fps=30, extra_args=['-vcodec', 'libx264']) 
  
    plt.show()

# call main 
if __name__ == '__main__': 
    main()